The CPX series is a different type of laboratory power supply designed to meet the need for flexibility in the choice of voltage and current. A conventional PSU has a fixed current limit giving a power capability that reduces directly with the output voltage. The TTi PowerFlex design of the CPX series enables higher currents to be generated at lower voltages within an overall power limit envelope. Each output can provide considerably higher current than a conventional PSU of the same maximum voltage and power (see power curve). Example voltage & current combinations for the CPX400D include 60V/7A, 42V/10A, 28V/15A, and 20V/20A.

The PowerFlex regulation system used on the CPX400 series combines a high frequency pre regulator with a linear post regulator to give both low noise and good transient response. Each output can operate in constant voltage or constant current mode with automatic crossover and mode indication.

Separate voltage and current meters on each output give a resolution of 10mV and 10mA. The fixed resolution avoids the misinterpretation of readings that
can occur with auto-ranging 3 or 31 digit meters where the decimal point position moves as the reading changes. Coarse and fine voltage controls are provided. The current control is logarithmic enabling low current levels to be set accurately. A View Settings button enables limit settings to be checked and adjusted at any time. Each output incorporates remote sense terminals that can be enabled or disabled at the flick of a switch. Remote sensing is essential for maintaining precise regulation at the load and true metering of the load voltage.

All CPX series power supplies are fitted with the new TTi designed output terminals. As well as acting as conventional binding posts for bare wires, spade connectors, or standard 4mm plugs, these can accept a 4mm safety plug with rigid insulating sleeve, a requirement specified by an increasing number of laboratories for safety reasons.
Limited opening length combined with raised insulated shoulders also make these terminals “touch proof” for voltages up to 250V.